#include<iostream>
#include<cmath>
using namespace std;
int main()
{
	int a,b,c,ans;
	cin>>a>>b>>c;
	if(b==0){cout<<a;return 0;}
	ans=a-ceil(c/b);
	if(ans<0)cout<<"0";
	cout<<ans;
	return 0;
}

20分 #3AC